Apparatus and process for retrieving information projected image-wise on a reusable storage film and erasing and restoring the storage film for subsequent reuse

ABSTRACT

These and other objects of the present invention are achieved by an apparatus and process for evaluating an image-wise exposed storage film positioned about a cylindrically-shaped member and linearly passed a cylindrically-shaped slot for interrogation by a light beam wherein a processing assembly is co-axially disposed within a processing chamber formed by the cylindrically-shaped member and wherein the processing assembly includes a plate member disposed for rotation in a plane perpendicular to the axis of the processing chamber and having a pentaprism and a fluorescence light sensor positioned proximate a contact point of the interrogating light beam with the storage film and further including converting electronics for the thus generated fluorescence light wherein after interrogation, the storage film is immediately restored in the same apparatus for subsequent reuse.

RELATED APPLICATIONS

This application claims the benefit of provisional application Ser. No.60/725,984, filed Oct. 13, 2005.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to radiographic imaging, and moreparticularly to an improved apparatus and process for digitallyretrieving information projected onto a reusable radiographic film andfor erasing and restoring the radiographic film immediately afterretrieval and in the same assembly.

2. Description of the Prior Art

Traditional x-ray imaging systems using silver-based films are beingreplaced by radiographic imaging systems using photo-stimulable phosphorimaging films or substrates eliminating the need for physical storage ofthe imaged film since digital retrieval of the image informationincludes input and computer storage permitting viewing of suchinformation on a viewer, such as CRT tube assembly. Additionally, suchcomputer stored image information permits facile electronic transmissionto any preselect location obviating physical transfer of the thus formedimage on the imaging film.

In U.S. Pat. No. 5,874,744 to Goodman, et al., assigned to the sameassignee as the present invention, there is disclosed a process andapparatus for processing radiographic information from an anisotropicstorage phosphor screen including an opto-electro-mechanical assembly toachieve faster scan of an interrogating beam and including detector andcomputer assembly, herein incorporated by reference.

In U.S. Pat. No. 6,599,004 to Thoms, there is disclosed an assembly forreading flexible storage films wherein the flexible storage film havingimage-wise projected information is positioned on a cylindrically-shapedsurface and is caused to be linearly moved there over while beinginterrogated or scanned via a slot by a light beam generated in ahelical line in a continuous manner from a point disposed at the axis ofthe cylindrically-shaped surface. The output fluorescence light orsignal generated at the actual point the light beam intersects thestorage film is received by a large diameter photomultiplier tubedisposed proximate the slot. Such output signal is recorded togetherwith positioning encorders to obtain an electrical image of the thusstored x-ray image on the storage foil. The configuration of thephotomultiplier and the distance there from to the interpretingelectronics results in a signal/noise ratio which while acceptable ifadvantageously decreased would provide more efficacious end result.

As used herein, the term “reusable storage film” is a flexible substrateformed with a layer of a photo-stimulable phosphors which is capable ofimaging with ionizing radiation or x-rays which after imaging may beinterrogated or scanned with a source of light energy to producephoto-stimulated luminescence information capable of being digitallyread and stored.

OBJECTS OF THE INVENTION

An object of the present invention is to provide an improved apparatusand process for interrogating and interpreting an image on a reusablestorage film moving past an accessible slot of an interrogating lightbeam and thereafter immediately restoring the storage film for reuse.

A further object of the present invention is to provide for an improvedapparatus and process for interrogating and interpreting an image on areusable storage film moving past an accessible slot of an interrogatinglight beam, the apparatus having incorporated therein a light cavity anda source of illumination for erasing the image from the storage filmsubsequent to the storage film being interrogated by a light beam toenergize the image and store same.

A still further object of the present invention is to provide for anovel apparatus and process for interrogating and interpreting an imageon a reusable storage film moving past an accessible slot of aninterrogating light beam wherein the belt and roller assembly of theapparatus is of an extended length so as to engage the storage film fromits insertion into the apparatus to a point subsequent to the erasinglight cavity.

A still further object of the present invention is to provide for animproved apparatus and process for interrogating and interpreting animage on a reusable storage film moving past an accessible slot of aninterrogating light beam wherein an erasing light cavity completelyremoves the stored image from the storage film permitting the immediatereuse of the storage film.

SUMMARY OF THE INVENTION

These and other objects of the present invention are achieved by anapparatus and process for evaluating an image-wise exposed storage filmpositioned about a cylindrically-shaped member and linearly passed acylindrically-shaped slot for interrogation by a light beam wherein aprocessing assembly is co-axially disposed within a processing chamberformed by the cylindrically-shaped member and wherein the processingassembly includes a plate member disposed for rotation in a planeperpendicular to the axis of the processing chamber and having apentaprism and a fluorescence light sensor positioned proximate acontact point of the interrogating light beam with the storage film andfurther including converting electronics for the thus generatedfluorescence light wherein after interrogation, the storage film isimmediately restored in the same apparatus for subsequent reuse.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects and advantages of the present invention will become morereadily apparent by reference to the following detailed descriptionthereof when taken with the accompanying drawings wherein like numeralsdesignate like parts throughout and wherein:

FIG. 1 is a partial cross-sectional view of the optical cavity andtransport mechanism of a scanner of the prior art;

FIG. 2 is a partial cross-sectional view of the optical cavity andtransport mechanism of the scanner of the present inventionincorporating an eraser and restoration means;

FIG. 3 is a partial cross sectional view of the optical cavityillustrating a second embodiment of the transport means in conjunctionwith the eraser and restoration means;

FIG. 4 is a front view of the scanner assembly with the transport meansremoved; and

FIG. 5 is a partial top view of the relationship between the transportmeans and the plate pressure rollers of the transport means illustratedin FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a partial cross-sectional view of the optical cavity 12 of ascanning mechanism 10 as presently exists in the prior art. Within theoptical cavity 12, there is positioned a laser tube assembly 14 whichtransmits a light source to a pentaprism 16 centrally mounted within theoptical cavity 12 on a shaft 18 secured to a pentaprism motor 20. Alsomounted on shaft 18 are a pair of fly wheels 22 and 24. The light sourcefrom the laser tube assembly 14 is redirected by the pentaprism 16, to ascanning slit 26. It is passed this scanning slit 26 that aphoto-stimulable phosphor imaging plate 28 passes having a latent imagethereon.

The photo-stimulable phosphor imaging plate 28 is inserted into a slot30 where it is engaged by a transport mechanism 32. The scanner detectsthe presence of a photo-stimulable phosphor imaging plate 28 by means ofan LED emitter 34 and associated fiber optic plate 36 to indicate to thescanning mechanism that a plate 28 is positioned for reading. Atransport frame 38 having a driver roller 40, idler roller 42, andtension roller 44 initiate movement of a transport belt 46 by means of atransport motor 48 causing the photo-stimulable phosphor imaging plate28 to pass through a set of light sealing brushes 50 and to pass infront of the scanning slit 26 where the photo-stimulable phosphorimaging plate 28 is interrogated by the light beam. The latent image onthe photo-stimulable phosphor imaging plate 28 is excited by the lightbeam and its contents collected by photomultiplier 52 and then stored ina CPU unit for viewing and archival purposes.

The photo-stimulable phosphor imaging plate 28 after having been read,is transported by means of the transport belt 46 and associated driverollers, etc. from the scanning assembly. At this time, thephoto-stimulable phosphor imaging plate 28 would require eraser orrestoration to remove the latent image thereon so that thephoto-stimulable phosphor imaging plate 28 could be reused. One mannerof erasing the photo-stimulable phosphor imaging plate 28 is to exposethe imaging plate 28 to a light source for a time sufficient to allowfor erasure and subsequent restoration of the plate for reuse. SeeApplicant's U.S. Pat. No. 6,778,776 for one manner of accomplishingrestoration of such an imaging plate.

Applicant's contribution to the scanning arts in this application is ascanner assembly in which the photo-stimulable phosphor imaging plate 28is erased or restored within the assembly after having been interrogatedsuch that the photo-stimulable phosphor imaging plate 28 exiting thescanner assembly has had its latent image removed, is restored, andimmediately ready for reuse. FIG. 2 is a partial cross-section of thescanning assembly of the present invention.

The interior of the optical cavity 12 remains generally identical to theprior art thus described. However, the scanner assembly is nowconfigurated with a light erasing cavity 60 positioned in the path ofthe photo-stimulable phosphor imaging plate 28, but subsequent to thescanning slit 26 where the latent image on the photo-stimulable phosphorimaging plate 28 is interrogated. In FIG. 2, the light erasing cavity 60is positioned below the scanning slit 26 and is in communication withthe pathway of the photo-stimulable phosphor imaging plate by means ofan erasing slit 62. Positioned within the light erasing cavity 60 wouldbe a light source 64 in communication with a power source so as todirect a light beam through the erasing slit 62 and onto thephoto-stimulable phosphor imaging plate 28 as it passes the erasing slit62. In the configuration illustrated in FIG. 2, the light source is anarray of multiple red/red orange LED's aimed radially outwardly so thatthe light emitted passes through the erasing slit 62. Additionally, thewalls of the eraser cavity 60 may be mirrored to enhance the lightemanating from eraser slit 62.

Since an additional process is now being performed in the scanner inaddition to the interrogation process on the photo-stimulable phosphorimaging plate 28, the transport means 32 for transporting thephoto-stimulable phosphor imaging plate must be extended. Whereas in thescanner assembly of the present art, the transport belt need onlytransport the photo-stimulable phosphor imaging plate 28 a distancesufficient for it to pass in front of the scanning slit 26 forinterrogation and then to exit the scanner, the transport assembly forthe present invention must be of longer configuration in order totransport the photo-stimulable phosphor imaging plate 28 past theerasing slit 62. In the configuration illustrated in FIG. 2, the numberof plate pressure rollers 39 is increased to accommodate the additionaldistance and the transport belt 46 is also extended.

FIG. 3 is a cross sectional view of the optical cavity and transportermeans illustrating a second embodiment of the transporter means whichdoes not require a reengineering of the transport means of the existingprior art in order to be able to transport the photo-stimulable phosphorimaging plate 28 past the eraser cavity 60. In this configuration, anadditional idler roller 42A is in belt communication with the driveroller 40 of the original transport means 32. Idler roller 42A ispositioned below the eraser cavity 60 and adjacent an additionalpressure plate roller 39A. In this configuration, the original transportbelt 46 would transport the photo-stimulable phosphor imaging plate 28past the eraser cavity 60 and then the lower pressure plate roller 39and the idler roller 42A would engage the photo-stimulable phosphorimaging plate 28 and transport it out of the scanner assembly or to adepository for reuse. This embodiment provides for more efficient use ofthe transport means of the prior art with minor reengineering. Therelationship between the idler roller 42A and the lower pressure plateroller 39 is illustrated in FIG. 5.

FIG. 4 is a side view of a scanning assembly illustrating the platepressure rollers 39 and their positioning within each verticalpassageway in which the photo-stimulable phosphor imaging plate 28 istransported. There are multiple transport means 32 associated with ascanner to accommodate multiple sized imaging plates hence there aremultiple sets of plate pressure rollers. Still further reference can behad to provisional application 60/693,020 of Applicant's directed to abelt and roller drive for the transport of an imaging plate within anopto-electrical mechanical scanning assembly.

FIG. 5 illustrates the relationship between lower pressure plate roller39A and idler roller 42A of the FIG. 3 embodiment. A bracket 70 isattached to the optical scanner on which the lower plate pressure roller39A is mounted. Lower plate pressure roller 39A is mounted on bearingson an idler axle 71 which is spring loaded with the center platepressure roller being of slightly larger circumference than those oneither side. The lower idler roller 42A is in communication with thedrive roller 40 by means of a timing belt relationship 35. In theconfiguration illustrated in FIG. 5, the idler rollers 42A are fixedlymounted on shaft 41 with the circumferential periphery 43 in tangentialcontact with the outer plate pressure rollers 39 such that the imagingplate passes thereby in an arcuate relationship.

The transport mechanism embodiments of FIGS. 2 and 3 can positivelyengage the photo-stimulable phosphor imaging plate 28 from its insertionpoint 30 to its ejection point and allows for an erasing light cavity 60to be positioned on the scanner assembly subsequent or downstream fromthe scanning slit 26 with the erasing light cavity having an erasureslit 62 and light source 64 which allows for the photo-stimulablephosphor imaging plate to be erased and restored and ready for reuseimmediately after it has been interrogated and read. It will berecognized that many different light sources can be utilized to erasethe photo-stimulable phosphor imaging plate and restore it for reuse.Applicant's use of an array of multiple red/red orange LED's is forexplanatory purposes, but this wave length is well suited for sucherasing and for not interfering with the data acquisition as this wavelength is filtered out by the blue filter on the photo-multiplier tube.

While the present invention has been described with respect to theexemplary embodiments thereof, it will be recognized by those ofordinary skill in the art that many modifications or changes can beachieved without departing from the spirit and scope of the invention.Therefore it is manifestly intended that the invention be limited onlyby the scope of the claims and the equivalence thereof.

1. An apparatus for retrieving information stored image-wise on astorage film and erasing said information stored image-wise on saidstorage film for reuse which comprises: a cylindrically-shapedpositioning surface for said storage film; and means for scanning andinterrogating said image projected on said reusable storage film andconcomitantly collecting light generated during scanning wherein saidscanning and collecting means is a processing assembly comprised of arotating plate member having a pentaprism and a light sensor positionedin axial alignment with a light beam directed by said pentaprism ontosaid storage film, said light sensor positioned proximate said lightgenerator; an eraser means positioned in an eraser cavity subsequent tosaid scanning interrogating and collecting means, said eraser meanssubjecting said reusable storage film to a light source for removal ofsaid information stored image-wise on said storage film; and means fortransporting said reusable storage film through said scanning means andsaid eraser means.
 2. An apparatus for retrieving information storedimage-wise on a storage film and erasing said information storedimage-wise on said storage film for reuse in accordance with claim 1wherein said light source for erasure of said information storeimage-wise on said storage film is an incandescent light source aimedradially outwardly from said eraser cavity and through said erasingslit.
 3. An apparatus for retrieving information stored image-wise on astorage film and erasing said information stored image-wise on saidstorage film for reuse in accordance with claim 1 wherein said lightsource is a plurality of light emitting diodes aimed radially outwardlyfrom said eraser cavity and through said erasing slit.
 4. An apparatusfor retrieving information stored image-wise on a storage film anderasing said information stored image-wise on said storage film forreuse in accordance with claim 1 wherein said plurality of lightemitting diodes comprised an array of red/red orange light emittingdiodes aimed radially outwardly from said eraser cavity and through saiderasing slit.
 5. An apparatus for retrieving information storageimage-wise on a storage film and erasing said information storedimage-wise on said storage film for reuse in accordance with claim 1wherein said eraser cavity is mirrored for light emanating enhancementfrom said eraser slit.
 6. An apparatus for retrieving informationstorage image-wise on a storage film and erasing said information storedimage-wise on said storage film for reuse comprising an extended meansfor transporting said reusable storage film through said scanning meansand said eraser means, said means for transporting comprising anextended transport belt for transporting said storage film passed saidscanning and interrogating portion of said scanner and passed saiderasing means portion of said scanner to said exit means of saidscanner.
 7. An apparatus for retrieving information stored image-wise ona storage film and erasing said information stored image-wise on saidstorage film for reuse in accordance with claim 1 wherein said scanningand said interrogating portion and said eraser portion of said apparatusare light segregated by means of a plurality of light blocking brushespositioned in the path of said storage film between said scanning andinterrogating means and said eraser means of said apparatus.
 8. Theprocess for retrieving information stored image-wise on a reusablestorage film and erasing said information stored image-wise on saidstorage film for reuse, which comprises: transporting an image-wisecontaining reusable storage film through a scanning and interrogationzone; rotating a plate member having a pentaprism and a light sensorpositioned in axial alignment with a light beam directed by saidpentaprism onto said storage film, said light sensor positionedproximate said light generator; interrogating said storage film with alight to digitally generate photostimulable luminescent light;collecting said digitally thus generated photostimulated luminescentlight proximate said scanning zone; transporting said reusable storagefilm through an eraser zone; generating a light source in said eraserzone within an eraser cavity having an eraser slit to erase saidinformation stored image-wise on said reusable storage film; andtransporting said erased reusable storage film out of said eraser zone.9. A process for retrieving information stored image-wise on a storagefilm and erasing said information stored image-wise on said storage filmfor reuse in accordance with claim 8 wherein said light source forremoval of said information store image-wise on said storage film is anincandescent light source aimed radially outwardly from said erasercavity and through said erasing slit.
 10. A process for retrievinginformation stored image-wise on a storage film and erasing saidinformation stored image-wise on said storage film for reuse inaccordance with claim 8 wherein said light source is a plurality oflight emitting diodes aimed radially outwardly from said eraser cavityand through said erasing slit.
 11. A process for retrieving informationstored image-wise on a storage film and erasing said information storedimage-wise on said storage film for reuse in accordance with claim 8wherein said plurality of light emitting diodes comprised an array ofred/red orange light emitting diodes aimed radially outwardly from saideraser cavity and through said erasing slit.
 12. A process forretrieving information storage image-wise on a storage film and erasingsaid information stored image-wise on said storage film for reuse inaccordance with claim 8 wherein said eraser cavity is mirrored for lightemanating enhancement from said eraser slit.
 13. A process forretrieving information storage image-wise on a storage film and erasingsaid information stored image-wise on said storage film for reuse inaccordance with claim 8 comprising an extended means for transportingsaid reusable storage film through said scanning means and said erasermeans, said means for transporting comprising an extended transport beltfor transporting said storage film passed said scanning andinterrogating zone of said scanner and passed said erasing means zone ofsaid scanner to said exit means of said scanner.
 14. A process forretrieving information stored image-wise on a storage film in accordancewith claim 8 wherein said scanning and said interrogating zone and saideraser zone of said apparatus are light segregated by means of aplurality of brushes blocking positioned in the path of said storagefilm between said scanning and interrogating zone and said eraser zoneof said apparatus.